Levoglucosenone (LGO; CAS No. 37112-31-5; systematic name (1S,5R)-6,8-dioxabicyclo[3.2.1]oct-2-en-4-one or 1,6-anhydro-3,4-dideoxy-β-D-glycero-hex-3-enopyranos-2-ulose) is an alternative, non-petroleum precursor which can be used as a building block chemical for producing various high-volume and value-added organic chemicals. LGO is notable for its highly functionalized, bicyclic structure which contains a chiral carbon, a double bond conjugated to a ketone, a protected aldehyde group, and two protected hydroxyl groups:

LGO is a highly dehydrated sugar that is conventionally derived from cellulose. It is a valuable intermediate in the synthesis of biologically active compounds, chiral therapeutic agents, and other value-added compounds. For a recent review of LGO as a chiral synthon, see Sarotti, Zanardi, Spanevello and Suárez (2012) “Recent Applications of Levoglucosenone as Chiral Synthon,” Current Organic Synthesis 9:439-459.
Conventionally, LGO is made via pyrolysis of cellulose-containing materials such as waste paper. See, for example, Shafizadeh, Furneaux, and Stevenson, (1979) “Some reactions of levoglucosenone,” Carbohydr. Res. 71:169-191. Yields, however, are quite low. The use of ionic liquids as solvents for LGO production has been proposed due to the solvation capabilities of the ionic liquids. However, significant challenges hinder the industrial use of ionic liquids for producing LGO. For example, due to the high cost of the ionic liquid solvent, the solvent must be quantitatively recovered and recycled to make the process economically attractive. The relatively low cellulose solubility (10-15 wt %) in ionic liquids, as well as the high viscosity and high toxicity of ionic liquids are also impeding factors. A number of routes to fabricate LGO are described in the prior art. These routes are summarized in Table 1:
TABLE 1Summary of Conventional LGO Fabrication RoutesFeedYieldTempscaleTLGOMethodCatalyst(° C.)(g)(min)(%)RefCatalytic fastSO42−/ZrO23353157.2-8.41pyrolysisH2SO42703107.582Zeolite55015trace3H2SO4, H3PO4,5234.83(NH4)2SO4,ZnCl2,Fe2(SO4)3Py-GC-MSH3PO43750.0021029-30[a]5H3PO4/(NH4)3PO49000.011550[b]6Zeolites5000.00511.77H3PO4/Fe3+5005 ×30-810−540[a]Ionic liquid[EMIM]CH3C6H4SO33000.052011.59[C4(mim)2] Cl21801205.510SulfolaneH2SO4, H3PO4240-3000.05442.211[a]Relative percent in bio-oil;[b]Peak area percent.